Jose Rodal

Massachusetts Institute of Technology | MIT

Prepared for Aerospace Safety Research and Data Institute, Lewis Research Center, National Aeronautics and Space Administration, Cleveland, Ohio. Originally presented as the first author's thesis, (Ph. D.) in the M.I.T., Dept. of Aeronautics and Astronautics, 1979. NASA Grant NGER 22-009-339. Includes bibliographical references (p. 351-368).

In the Alcubierre warp-drive spacetime, we investigate the following scalar curvature invariants: the scalar I, derived from a quadratic contraction of the Weyl tensor, the trace R of the Ricci tensor, and the quadratic r1 and cubic r2 invariants from the trace-adjusted Ricci tensor. In four-dimensional spacetime the trace-adjusted Einstein and Ric...

In the Alcubierre warp-drive spacetime, we investigate the following scalar curvature invariants: the scalar I, derived from a quadratic contraction of the Weyl tensor, the trace R of the Ricci tensor, and the quadratic r1 and cubic r2 invariants from the trace-adjusted Ricci tensor. In four-dimensional spacetime the trace-adjusted Einstein and Ric...

A frequency-dependent Machian effect previously put forward by Woodward (that for a body undergoing mass–energy fluctuations, the second time derivative of the mass–energy density is a source of a gravitational field) is discussed within Einstein’s theory and justified using Hoyle–Narlikar’s conformal gravitational theory. It is shown that Einstein...

The Deep Space Gateway (DSG) proposed for cis-lunar space offers an opportunity to both improve tests of fundamental physics and to develop chronometric navigation techniques for the human exploration of Mars and beyond. Here we outline how the DSG, equipped with highly accurate optical atomic clocks and optical phase coherent links with the Earth...

It has been argued that the anomalous results found by NASA's Brady et.al for microwave cavities (that supposedly act as a propellant-less thruster) cannot be due to thermal effects because a) the temperature increase would need to amply exceed several degrees C to be explained by thermal effects and b) thermal effects take place too slowly (minute...

This study was intended to contribute to the development of more rational practical methods for predicting the transient responses of structures which are subjected to transient and impact loads. Attention is restricted to the global structural response; local (or stress-wave- induced) response is not included. The use of higher-order assumed-...

What are the limitations of polymer covers used in soft-nip calendering? Why have polymer covers reportedly taken 25% of the available positions in U.S. supercalenders away from conventional cotton-filled rolls? How long can these polymer covers run between re-finishings of the cover's surface and what is the physical phenomenon responsible for thi...

Numerical calculations (finite-element analysis) of plastic (permanent) deformation of a paper web during soft-nip calendering are presented. Paper is modeled as a porous, cellular, solid material. Stress and deformation results are discussed in relation to theories previously presented in the literature. Emphasis is placed on the relative role of...

The calendering of paper (including on-machine and off-machine soft-nip calendering) has largely evolved as an empirical art without a theoretical basis for what actually occurs to the paper in the process. On the other hand, there have been theoretical models for the calendering of metals for quite some time. Calendering of paper is significantly...

A brief review of pertinent works in the field of contact mechanics is made, with emphasis placed on works related to the calendering process, starting with Hertz' assumptions and ending with non-Hertzian effects, including thin-layer covered rolls, sliding, sticking, "micro-slip," and friction effects. Emphasis is placed on the effect that changin...

A theoretical, phenomenological description is presented for the changes produced on a paper web by soft-nip or hard-nip calendering both on-machine and off-machine. Experimental results compare well with theories in the relevant literature. Cotton-filled rolls have been successfully replaced by rolls covered with polymer composites. These new roll...

A brief review of pertinent works in the field of contact mechanics is made, with emphasis placed on works related to the calendering process, starting with Hertz, assumptions and ending with non-Hertzian effects, including thin-layer covered rolls, sliding, sticking, “micro-slip”, and friction effects. Emphasis is placed on the effect that changin...

The formulation of the problem of finite elastic-viscoplastic deformation of thin beams is described. The finite element analysis of a representative problem is presented and various solution methods are surveyed.

Two computer programs are described for predicting the transient large deflection elastic viscoplastic responses of thin single layer, initially flat unstiffened or integrally stiffened, Kirchhoff-Lov ductile metal panels. The PLATE 1 program pertains to structural responses produced by prescribed externally applied transient loading or prescribed...

Finite element modeling alternatives as well as the utility and limitations of the two dimensional structural response computer code CIVM-JET 4B for predicting the transient, large deflection, elastic plastic, structural responses of two dimensional beam and/or ring structures which are subjected to rigid fragment impact were investigated. The appl...

INSTRUCTION FOR THE USE OF THE CIVM-JET4C FINITE-STRAIN COMPUTER CODE TO CALCULATE THE TRANSIENT STRUCTURAL RESPONSES OF PARTIAL AND/OR COMPLETE ARBITRARILY-CURVED RINGS SUBJECTED TO FRAGMENT IMPACT

Investigations on the impact-interaction of both complex engine rotor fragments and simple fragments with various types of single-layer and multilayer containment structures were reviewed. The resulting data were used (1) to develop empirical design rules and (2) to evaluate proposed theoretical methods for predicting the impact induced responses o...

The sheet explosive loading technique (SELT) was employed to obtain elastic-plastic, large deflection 3-d transient and/or permanent strain data on simple well defined structural specimens and materials: initially-flat 6061-T651 aluminum panels with all four sides ideally clamped via integral construction. The SELT loading technique was chosen sinc...

Theoretical methods were developed for predicting the large-deflection elastic-plastic transient structural responses of metal containment or deflector (C/D) structures to cope with rotor burst fragment impact attack. For two-dimensional C/D structures both, finite element and finite difference analysis methods were employed to analyze structural r...

Protective structures of nuclear power plants may be subjected to impact from fragments from aircraft engine rotors and stationary power plant turbine rotors. Furthermore, it is assumed that the structures intended to contain these fragments consist of initially-isotropic elastic-plastic metals. Pertinent experimental data discussed here on fragmen...

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1979. Supervised by Emmett A. Witmer, Theodore H.H. Pian, and John Dugundji. Vita. Includes bibliographical references.